Process for the preparation of aminoazo compounds



Patented Apro 7, 1925i stares KARL HEUSNEB aerate? entrant @FWMK A ND MAX SIMON, LEVERKUSEN, NEAR COLOGNE-ON-THE-RHINE,

GERMANY, ASSIGNORS T FARBENFABRIKEN VORM. FRIEDR. BAYER & ('30., 0F LEVEEKUSEN, NEAR COLOGNE-O'N-THE-RHINE, GERMANY.

PROCESS FOR THE PREPARATION OF AMINOAZ O COMPOUNDS.

No Drawing. Application filed July 24,

To all whom it may concern:

Be it known that we, KARL HEUSNER and MAX SIMON, citizens of Germany, residing at Leverkusen, near Cologne-on-the-Rhine, in the State of Prussia, Germany, have invented new and useful Improvements in Processes for the Preparation of Aminoazo Compounds, of which the following is a specification.

It has been found that the 'al ha-naphthylsulfaminic acid described by iria (Ann. 78 (1851:) p. 31 onwards) as a thionaphthamic acid (in spite of the presence ofa markedly acidic sulfuric acid residue in the aminogroup) may be combined with diazo-compounds and that the entry of the diazo-group occurs almost quantitatively in the paraposition to the sulfamino-group. On the other hand it is well known that when using alpha-naphthylamine that on the average from to per cent of the valueless orthocompound are produced with the para-compound, accorjing to the choice of the diazotization co iponents and the condition of coupling.

As the splitting off of the sulfo-group takes place easily on warming in aqueous mineral acid solution, dyestufls may be obtained by the aid of alpha-naphthylsulfaminio acid, which compared with those obtained from alpha-naphthylamine give considerably higher yields and are moreover of a higher purity than these.

Our invention consists therefore in com 1924. Serial No. 727,984.

bining any diazo compound with alphanaphthyl-sulfaminic acid. This reaction is represented by the formula:

11 Se n H soin In order to illustrate the new process more fully the following examples are given Emample 1.10.7 parts by weight of paratoluidine are diazotized in the customary manner and coupled at ice temperature with a solution of 24.5 parts by weight of sodium alpha-naphthylsulfaminate and 28 parts by weight of soda ash. After stirring for several hours the coupling is terminated. The dye so obtained is a yellow precipitate. It may be filtered oil and dried without decomposition. It is soluble in hot water to a clear yellow solution. The splitting off of the sulfo-group takes place on acidification of the coupled product with 100 parts by weight of 19 B. hydrochloric acid whilst warming. The higher the mixture is heated, the sooner the splitting off of the sulfogroup is completed. The elimination of the sulfo-group occurs without an loss in yield.

The reactions involved can lie formulated as follows:

CHaO-NEN NH o1 sonar on N-N-i Z-N QOa-H In place of para-toluidine other diazotization components may be taken as for instance aniline, chloroanilines, aminopheno lethers, monoacidylphenylenediamines, nitranilines and their homologues, alphaand beta-naphthylaniines, aminonaphtholethers,

(EON-118KB,

aminoanthraquinones, .dia'mtinodiphenyl derivatives etc.

24.5 parts by weight of sodium-alpha-naphthylsulfaminate and 20 parts Toy weight of 100 per cent sodium acetate at about 10 C, The coupling is completed after several hours stirring and a clear brown-yellow solution 5 results. For the purpose of splitting ofi the sulfo group the product of the coupling is H S 03H has means? rendered acid with 100 parts by weight of hydrochloric acid (19 Be.) and is warmed for some time.

The reactions involved can be formulated 10 as follows:

NHg

80,3 sons We claim A process for the preparation of sulfaminoazo bodies consisting in coupling diazo- :5 compounds of any kind with alpha-naphthylsulfaminic acid.

In testimony whereof we have hereunto set our hands.

KARL HEUSNER. MAX SIMON. 

